: the totality in psychology of sensations, perceptions, ideas, attitudes, and feelings of which an individual or a group is aware at any given time or within a given time span <altered states of consciousness, such as sleep, dreaming and hypnosis—Bob Gaines>
: waking life (as that to which one returns after sleep, trance, or fever) in which one's normal mental powers are present <the ether wore off and the patient regained consciousness>
: the upper part of mental life of which the person is aware as contrasted with unconscious processes
Quality or state of being aware. As applied to the lower animals, consciousness refers to the capacity for sensation and, usually, simple volition. In higher animals, this capacity may also include thinking and emotion. In human beings, consciousness is understood to include meta-awareness, an awareness that one is aware. The term also refers broadly to the upper level of mental life of which the person is aware, as contrasted with unconscious processes. Levels of consciousness (e.g., attention vs. sleep) are correlated with patterns of electrical activity in the brain (brain waves). See also philosophy of mind.